Best Party Ever? Katy Perry Celebrates Kacey Musgraves's 26th with a Roller Disco

To celebrate her 26th birthday, Kacey Musgraves threw a private roller disco birthday bash at Skateville in Burnsville, Minnesota, on Thursday night, complete with glow sticks, party hats and cake.

The singer was joined by a handful of pals and Katy Perry, with whom she's currently touring (the two play Minneapolis Friday night). And by the looks of the stars' Instagram feeds, it was a heckuva lot of fun. Read on to see some of the night's best snaps!